python基础之作业3----三级菜单小练习

data = {    "华为技术":{        "产品与解决方案":{            "云核心网":{"云核心网研发管理部","云核心网平台开发部"},            "无线网络产品线":{"无线研发管理部","无线平台开发部"  },        },        "2012实验室":{            "质量与运营部":{"上研质量与运营部","成研质量与运营部"},        },        "物联网":{            "车联网":{"车联网研发管理部","车联网开发管理部"},        },    },}

exit_flag = False  # 默认不退出，

while not exit_flag:    for i in data:        print(i)    user_choice = input("请选择您的一级SAP部门信息: ")    if user_choice in data:        while not exit_flag:            for j in data[user_choice]:                print("\t",j)            user_choice_2 = input("继续选择您的二级SAP信息： ")            if user_choice_2 in data[user_choice]:  #[user_choice_2]:                while not exit_flag:                    for k in data[user_choice][user_choice_2]:#[user_choice_3]:                        print("\t\t",k)                    user_choice_3 = input("继续选择您的三级SAP信息： ")                    if user_choice_3 in data[user_choice][user_choice_2]:                        for l in data[user_choice][user_choice_2][user_choice_3]:                            print("\t\t",l)                        user_choice_4 = input("达到最后一层了，返回请输入back:")                        if user_choice_4 == "back":                            break                        elif user_choice_4 == "exit":                            exit_flag = True                            #pass 如果写pass，可以作为一个占位符，                    if user_choice_3 == "back":                        break                    elif user_choice_3 == "exit":                            exit_flag = True            if user_choice_2 == "back":                break            elif user_choice_2 == "exit":                exit_flag = True

elif user_choice == "exit":        exit_flag = True